How to Make It
Whisk together the flour, baking powder, 1 teaspoon of ground ginger, and salt in a medium bowl; set aside.
Beat the butter, brown sugar, and ginger with an electric mixer on medium-high speed until light and fluffy, 2 to 3 minutes. Beat in the egg, molasses, and vanilla. Reduce speed to low and add the flour mixture, mixing just until combined (do not overmix). Fold in the chocolate chips. Chill for at least 1 hour and up to 3 days.
Heat oven to 350° F with the racks in the upper and lower thirds. Line 2 baking sheets with parchment. Whisk together the granulated sugar and the remaining ½ teaspoon of ground ginger in a small bowl. Roll 2 tablespoonfuls of the dough into balls; roll in the sugar to coat. Place on the prepared baking sheets, spacing them 2 inches apart.
Bake, in batches, rotating the sheets halfway through, until the edges are firm and the cookies are cracked on top, 14 to 16 minutes. Cool slightly on the baking sheets, then transfer to a wire rack to cool completely.
Storage suggestion: Keep the cookies in an airtight container at room temperature for up to 5 days.